Switched to a GNG style "big block" swingarm coming soon!!

yeah, at 45kph=28mph like I use to drive with my little bafang SWXH offroad, this looks really different :( Dont get 50km=31miles with my 555Wh battery at that speed. If I go slower that's no problem, but who wants to drive slow?
 
I hear you there but I think my main demographic is the single track and technical trail type of enthusiast and in that terrain 28mph will likely leave you injured! Lol! My average power consumption in varied terrain as I usually do is around 500 watts, more when climbing and as low as 200 in flat areas. I have been testing my bike for some time now and feel most cyclists will be more than pleased with what it will do. I'm hoping the new design you suggested with this converted motor will be even better!
 
Moved the swing arm and longer wheelbase..

photobucket-54800-1357880260320.jpg
 
Lol moved it down like 5"!
 
Oh I see why now, its cause I cut the seat support area down to match to lower it a bit. That's why you can't see the difference..
 
Hmmm...your last picture is exactly the same as the previous one. It even has he same photobucket image number. Something's not right, me thinks.
 
Oops... my fault!! Must have copied the wrong one! Here is another I just did with battery mock ups in place single file so it stays thin.. hopefully no thicker than the thickest part of the MAC once I shave it as much as possible..

photobucket-53284-1358028741160.jpg
 
You can see the pivot is just barely higher than the output of the motor, and I would consider this with rider so its a fairly neutral position for suspension compression.
 
I'm thinking 10ga. Or .100"
 
Whiplash said:
I'm thinking 10ga. Or .100"
Click to expand...

This will be heavy :D 2.5mm or 0.1" is ok for a swing arm, but for the frame? You should reinforce parts like the swing arm mount, BB and fork tube either way. I cannot really imagine how this will look in the end, maybe that' why I use CAD :D BTW... no comments about my comparison? http://endless-sphere.com/forums/viewtopic.php?f=28&t=46813&p=687016#p686874 I saw a 9FET in your last pic, this one wont stand 50amps bat current limit, like I calculated :(

maybe you can also ask Silvio for some dimensions, just as a reference? He did weld such a nice frame, sadly it's from steel http://endless-sphere.com/forums/viewtopic.php?f=28&t=42262
 
Yeah the 9 fet may end up being a 12 but I can always change that later.
 
The thickness is actually thinner than Timma has used successfully in his builds. I am not worried about the extra pound or two I am trading for strength. Especially since I will not be heat treating these frames..

http://endless-sphere.com/forums/viewtopic.php?f=6&t=34719
 
Maybe it's not that great idea not to do heat treating :?

bigmoose said:
Just wanted to ensure this piece of advice got caught. Welding on aluminum removes all of the heat treatment in the heat affected zone even if done with TIG. For example 6061T6 aluminum alloy has a yield of 40000 psi and a elongation at break of 12%. Dead soft it becomes 6061T0 with a yield of 8000 psi and an elongation at break of 25 to 30%

I have heard of DIY heat treatments, but best bet to a professional that can put the completed frame in his heat treatment furnace.
Click to expand...

I can only sign what bigmoose wrote in the other thread (good reference btw). Even some off the shelf bikes use thicker material than 0.1". But they do not use as MUCH material as you will use on yours I guess, there is a lot of alloy around the battery adding strength to the "box". Maybe you should use some inner stiffeners. Off course it maybe a easier to use thicker material than having to do rework after short time. Heat treatment should not be too expensive, since the temperature needed is relatively for alloy. If you really want to come around this, you should at least do some rough calcs about this. You could just estimate the needed material thickness by comparing with a similar frame, but I guess you wont find any for comparison :?

What sheet material do you wanna use?
 
I'll just stick with a tried and true combo that Timma has done quite a few times no with no problems at all. No heat treatment no problem...
 
Nice to hear that. This way this whole thing sounds way more affordable :D Which combo does he use, or is it a secret?

DIY heat treatment also sound like worth thinking about... maybe you dont need much more than a torch to get rid of at least some tensile at the weld spots?

this one maybe also interesting for you, the Conway e-rider frame geometry: http://e-rider-shop.de/shop_content.php?coID=10
 
crossbreak said:
Nice to hear that. This way this whole thing sounds way more affordable :D Which combo does he use, or is it a secret?

DIY heat treatment also sound like worth thinking about... maybe you dont need much more than a torch to get rid of at least some tensile at the weld spots?

this one maybe also interesting for you, the Conway e-rider frame geometry: http://e-rider-shop.de/shop_content.php?coID=10
Click to expand...


I did consider the torch annealing method, we'll see how it goes...
 
crossbreak said:
Maybe it's not that great idea not to do heat treating :?

bigmoose said:
Just wanted to ensure this piece of advice got caught. Welding on aluminum removes all of the heat treatment in the heat affected zone even if done with TIG. For example 6061T6 aluminum alloy has a yield of 40000 psi and a elongation at break of 12%. Dead soft it becomes 6061T0 with a yield of 8000 psi and an elongation at break of 25 to 30%

I have heard of DIY heat treatments, but best bet to a professional that can put the completed frame in his heat treatment furnace.
Click to expand...

I can only sign what bigmoose wrote in the other thread (good reference btw). Even some off the shelf bikes use thicker material than 0.1". But they do not use as MUCH material as you will use on yours I guess, there is a lot of alloy around the battery adding strength to the "box". Maybe you should use some inner stiffeners. Off course it maybe a easier to use thicker material than having to do rework after short time. Heat treatment should not be too expensive, since the temperature needed is relatively for alloy. If you really want to come around this, you should at least do some rough calcs about this. You could just estimate the needed material thickness by comparing with a similar frame, but I guess you wont find any for comparison :?

What sheet material do you wanna use?
Click to expand...




One thing to take into consideration is the length of the welds themselves, with my design, there won't be a single spot with less than 10" of weld holding the frame to any high stress area like the bottom bracket or the head tube, and even at 8000 psi, its MOORE than adequate for a bicycle frame. I intend to build the head tube and BB and swing arm pivots from very thick wall as well..
 
crossbreak said:
this one maybe also interesting for you, the Conway e-rider frame geometry: http://e-rider-shop.de/shop_content.php?coID=10
Click to expand...

Now there is a sensible rear suspension geometry!

29_0.JPG


I'll just say it one more time and then I'll shut up: The proposed, even the revised one, geometry by whiplaash will not produce good results. It just simply won't work well at all. Why compromise function? :(
 
Why do you say that? The pivot is nearly even with the output of the motor? I love that bike but TRULY believe the reason ebikes have not caught on in the US is cost, there are some cool bikes available but they are TRULY RIDICULOUS in cost. I love the stealth but the price is insane, I can buy an awesome dual sport MX bike for that price. What I'm trying to do is get a bike that work well and will climb ANYTHING and then get you back home on the road at 35ish MPH. If you feel a little power bob under load while climbing WHO CARES. Its not like you are pushing the pedals and it makes it harder, and that is the only reason to worry about it... Besides I highly doubt it will even be noticeable...
 
I agree that at this stage, a single pivot is acceptable for an E-bike that is rarely pedaled. Here's a pic of the eSpire, that may be useful to discuss. Buyers can spec a low-end or a high-end fork, but welding on the frame is something that few are willing to do, and those who would do that are more like to weld up their own frame instead of pay a premium price for something they know they's cut and re-weld right away...

Espire1.jpg
 
Thanks for that, I have always liked those bikes as well. I'm going to continue to play with swing arm placement but it is unlikely it will change drastically. When I was doing my original mid drive build, a LOT of people said it was of no benefit to go through the gears or the chain would break, now everybody wants mid drive bikes! I proved them all wrong and I am fairly certain this is another of those times. Trust me I won't build it if I don't think it'll work. Thanks for seeing the light Spinning mags!
 
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